The WeiShi (WS) family of the multiple launch rocket systems was developed by Sichuan Aerospace Industry Corporation (SCAIC, also known as Base 062) in Chengdu, Sichuan Province. The weapon system was developed for the export market, but has yet received any order. Currently there are four models available: the 302mm WS-1 (100km range), the improved 302mm WS-1B (180km range), the 122mm WS-1E (40km), and the latest 400mm WS-2 (200km range).

SCAIC began to develop an unguided large-calibre multiple launch rocket system for the PLA ground forces in the late 1980s. The resulted WeiShi-1 (WS-1) 302mm, 4-tube multiple rocket system was first tested in 1990. However, the weapon system failed to impress the PLA, and no production order was received. The ground equipment of the WS-1 comprises: a rocket launch truck, a transport and loading truck and a firing command truck.

The free rocket used by the WS-1 and WS-1B consists of the warhead and fuse, an FG-42/43 rocket motor and the tail section. The FG-42/43 rocket motor is a single chamber, solid rocket motor with an advanced hydroxy-terminated polybutadine (HTPB) composition rocket propellant. The rocket of the WS-2 system features four control surfaces in the middle section of the rocket for terminal guidance.

The rocket can be fitted with various types of warheads including anti-armour/personnel submunition, blasting, fuel air explosive (FAE), and high-explosive (HE). The ZDB-2 blasting warhead is loaded with steel balls and prefabricated fragments. The SZB-1 submunition warhead is designed to destroy large area targets such as armour formation and infantry troops. When the SZB-1 submunition warhead detonates, around 500 bullets are expelled under high pressure.

The launch truck is available in a number of variants. The MF-4 launch truck is based on a Chinese indigenous 6X6 truck chassis. The HF-4 launch truck is based on the more capable Tiema XC2200 6X6 truck. The WS-2 uses a heavier 8X8 Taian TAS-5380 truck chassis. The launch tubes have an elevation range of 0° to 60° and azimuth range of -30° to +30°. The truck is equipped with four hydraulically operated stabilisers which are lowered in preparation for the rocket launch.